On a Friday, it's MORNING EDITION from NPR News. I'm Steve Inskeep. Let's look more closely now at the competition for control of the South China Sea. That's a strategic body of water surrounded by growing Asian nations like the Philippines, Vietnam and of course, China. Many nations have made overlapping claims for that sea and the resources beneath it. Since several nations are U.S. allies, it's a conflict in which the United States has a big interest.

This week, those claims prompted something just shy of gunfire. China moved an oil rig and began drilling in an area also claimed by Vietnam. Each side is now blaming the other for ramming its ships. NPR's Anthony Kuhn starts our coverage.

(SOUNDBITE OF VIDEO)

ANTHONY KUHN, BYLINE: In Hanoi on Wednesday, Vietnamese Coast Guard officials showed this video which they said shows Chinese vessels colliding with their ships and firing a water canon at them. They said six government staff were injured as they attempted to repel an intrusion into Vietnamese waters. On Wednesday, Chinese foreign ministry official Yi Xianliang told reporters that Vietnam was the aggressor and had rammed Chinese ships 171 times over five days.

China was deeply shocked, he added, by the behavior of its Vietnamese brothers and comrades.

YI XIANLIANG: (Speaking Chinese)

KUHN: I believe the Vietnamese will become more rational, stop their interference and pull out their ships, he said.

The oil rig is located about 120 nautical miles from Vietnam's Ly Son Island, and about 20 miles south of the Paracel Islands claimed by both China and Vietnam. China says it will continue its drilling operations in the area, which is believed to be rich in oil and gas, until Aug. 15th.